FUNGOID PESTS OF CULTIVATED PLANTS. 155 



green parts, and internally exhibits very little mycelium ; the pustules are 

 without definite receptacles, and the conidia are produced on short stalks 

 within definite cells ; when mature they escape by rupture of the cuticle, 

 and lie like a crust on the surface until dissolved by moisture (5-6 x 2J ju), 

 when they float away to infect other parts. (Fig. 22.) 



Gard. Chron. July 8, 1893, fig. 10 ; Mass. PL Dis. p. 279 ; Sacc. SylL 

 iii. 3755 ; Thiim. Pilz. Wein. p. 9 t. 3, f. 24 ; Thiim. Pock. d. Wein, 

 (1880) ; Tubeuf, Dis. p. 484. 



Fresh compost at the roots recommended, Gard. Chron. Aug. 27, 

 1904, p. 153. 



White rot of Grapes, Coniothyrium diplodiella (Speg.), occurs on the 

 fruit, leaves, and rarely on twigs. It is uncertain whether it is truly a 

 parasite. The coloured sporules are 7-11 x5j p. This pest has recently 

 been investigated in Hungary by Istvanffi, and the results published in 

 " Annales de 1'Instit. Ampelologique Boy. Hongrois," ii. 1902, with 

 24 coloured plates, in which it is claimed to be a destructive parasite. 



Squirt Berry, Phoma tuberculata (McAlp.), is an Australian species. 



Grape Hendersonia, Hendersons tenuipes (Me Alp.), occurs on ripe 

 Grapes in Australia, but we doubt its parasitism, and also whether it may 

 not rather be a Pestalozzia, with delicate cilia not observed. It need 

 cause no alarm in Europe. 



VINE LEAF-SPOT MOULD. 

 Cercospora viticola (Sacc.), PI. XIII. fig. 6. 



Massee says simply that it forms " brown spots on vine-leaves, and is 

 most abundant during a damp season. Most abundant on the lower 

 shaded leaves." Still we are in doubt whether he records it as British, 

 and although we have seen foreign specimens, we have had none reputed 

 to be indigenous. 



The spots occur on both sides of the leaves, and are somewhat 

 circular or irregular (2-10 mm.), becoming ochraceous, not distinctly 

 marginate; threads on the under surface in tufts (50-200x4-5^), 

 septate, ochre. Conidia elongated, attenuated upwards, three- to four- 

 septate (50-70 x 7-8 /u), with a tinge of olive. 



This is recorded for France, Germany, Portugal, Austria, and Italy, 

 but must be quite distinct from Isariopsis clavispora, with which it has 

 been confounded. 



Sacc. Syll. iv. 2200 ; Mass. PL Dis. pp. 319, 439. 



Another species (Cercospora Rossleri), with shorter, obtuser, and more 

 cylindrical conidia, is recorded on living vine-leaves for France, Portugal, 

 Austria, and Italy (50-60 x 7 /*). 



A species called Cercospora sessilis (Sorok.) is recorded from Russia. 



